The present invention relates to improvements in controlling the flushing of toilets and urinals.
Known metering valves for flushing toilets and urinals typically include a slow closing valve mechanism for delivering a metered volume of water to a fixture. This type of valve does not achieve precise control of the flow rate or volume. The result can be excessive water consumption and poor flushing performance. To overcome such problems, there have been efforts to directly measure and control water flow in flush controllers.
U.S. Pat. No. 4,916,762 discloses a metered water control system for flush tanks including a water wheel turned by flow through a valve and a mechanical system including a gear and a notched cam for closing the valve after flow of a predetermined quantity of water.
U.S. Pat. No. 4,989,277 discloses a toilet flushing device including a flow rate sensor for detecting a flow rate that is compared with a programmed value read from memory. A flow rate control valve is operated in accordance with the comparison to provide a programmed flow rate pattern.
U.S. Pat. No. 5,806,556 discloses a metering valve including a flow turbine for measuring flow through an opened valve. Rotation of turbine wheel is transmitted to a cam through a reducing gear assembly and a lost motion connection in order to close the valve after a predetermined flow volume.
U.S. Pat. No. 6,041,809 discloses a flush control valve assembly with a burst valve for providing a larger, siphoning flow and a bypass valve for providing a smaller, trap reseal flow. The duration and flow volume of the larger flow is determined by the characteristics of the burst valve components, and the duration and flow volume of the smaller flow are determined by a flow turbine, a gear assembly and a control mechanism.
U.S. Pat. No. 5,469,586 discloses a flushing device including a microprocessor for operating a single variable flow valve at varied flow rates to provide stepped variations in flow. Flow rate patterns including urinal and toilet flush patterns are stored in memory. Other microprocessor based flushing systems are disclosed in U.S. Pat. Nos. 5,508,510 and 5,769,120
These prior art arrangements have not solved the problem of precise, adjustable flow control, particularly for siphon flush toilet applications where the fixture is supplied with an initial burst of water for siphon flushing and a subsequent low flow for trap reseal. It would be desirable to provide a flush controller that can accurately measure water flow and that can be precisely controlled to avoid unnecessary water consumption and to provide effective flushing action.
Known automated fixture flushing systems include the capability for sensing the presence of a user. The goal is to determine when use of the sanitary fixture has terminated so that the fixture can be flushed after use.
U.S. Pat. Nos. 4,793,588 and 4,805,247 disclose flush valve systems having an infra red sensor mechanisms including an infra red transmitter and an infra red receiver.
U.S. Pat. No. 5,482,250 discloses a flushing device with first and second infra red sensing systems. One of these systems detects the presence of a user at a sanitary fixture, and the other detects the presence of the hand of a user in a different region and permits the user to manually initiate a flush operation. A refracting element is used to bend the infra red beam a desired angle toward a toiler user region.
U.S. Pat. No. 4,309,781 discloses an automatic flushing system with an infra red light emitting diode light source and a photosensor. A lens system includes a lens angled to prevent false activation from reflective surfaces. Light reflected from the source to the photosensor by a proximate user for a preselected time results in initiation of a flush operation.
Performance of these known systems is inconsistent because the presence and amount of reflected light is dependent on extraneous factors such as reflection characteristics of different types of clothing and the like. Adjustment of sensitivity is necessary. Increased sensitivity can result in false readings, and reduced sensitivity can result in the failure to detect a user when present. It would be desirable to provide a flush controller having a user detection system that operates reliably despite reflectivity variations and that is able not only to detect the presence of a user in a detection area, but also to locate the position of the user within the area.
Known metering flush controllers of the type including slow acting valve mechanisms can be configured to supply a urinal or a toilet by selecting specific components of the valve mechanism to provide the needed flow characteristic. Known valves of this type can be connected to a water supply at the right or the left side. Electronically operated systems have not had these capabilities. It would be desirable to provide a flush controller that can be configured by the selection, orientation and location of components for toilet or urinal applications with right or left water entry.
A principal object of the invention is to provide improved methods for controlling a flush controller for a sanitary fixture. Other objects are to provide a method for accurately metering flow through a valve assembly having low and high flow valves by measuring flow through the low flow valve and computing total flow by correcting for non linear flow when the high flow valve is partly open; to provide a method for not only detecting but also for locating the position of a user in a user detection field in front of a sanitary fixture; to provide a method for configuring a flush controller for toilet or urinal control with right or left water entry and for detecting the configuration and initializing a control system accordingly; and to provide flush control methods overcoming shortcomings in known flush control arrangements.
In brief, in accordance with the invention there is provided a method for flushing a sanitary fixture including opening a low flow valve between a water supply and the sanitary fixture and opening a high flow valve between the water supply and the sanitary fixture. The method includes keeping a running count of flow through the low flow valve and commanding a closing the high flow valve when the running count reaches a closing count. The closing count is developed by using a baseline count derived from a proportional flow relationship between the valve open flow rates of the high and low flow valves, and from an added correction factor to account for nonproportional flows when the high flow valve is partly open.
In brief, in accordance with the invention there is provided a method for detecting a user in a user detection field in front of a flush controller for a sanitary fixture. The method includes emitting light into the user detection field and sensing the amounts of light reflected from spaced locations in the user detection field. A ratio of the sensed amounts is determined The ratio is used to locate a user in the user detection field.
In brief, in accordance with another aspect of the invention there is provided a method for configuring and operating a flush controller for toilet or urinal control with right or left water inlet. The method includes positioning a valve assembly so that an inlet of the valve assembly is directed either to the right or to the left for a corresponding right or left water inlet connection. A circuit board having an array of electrical terminals is oriented in one of two positions for a right or left water inlet connection respectively. Electrical components of the valve assembly are interconnected to selected terminals of the circuit board in a plurality of different connection patterns for a plurality of different flush controller configurations. The array of circuit board terminals is tested to detect a connection pattern corresponding to a flush controller configuration and a flush controller operating system is initialized with information about the connection pattern.